Stereotactic body radiotherapy with helical TomoTherapy for medically inoperable early stage primary and second-primary non-small-cell lung neoplasm: 1-year outcome and toxicity analysis

Comparison of long-term outcomes of stereotactic body radiotherapy (SBRT) via Helical tomotherapy for early-stage lung cancer with or without pathological proof

BACKGROUND

Stereotactic body radio therapy (SBRT) has emerged as a standard treatment option for nonsurgical candidates with early-stage non-small cell lung cancer (NSCLC). Pathological proof is sometimes difficult to obtain in patients with solitary pulmonary nodules (SPNs). We aimed to compare the clinical outcomes of stereotactic body radiotherapy via helical tomotherapy (HT-SBRT) for early-stage lung cancer patients with or without a pathological diagnosis.

METHODS

Between June 2011 and December 2016, we treated 119 lung cancer patients with HT-SBRT, including 55 with a clinical diagnosis and 64 with a pathological diagnosis. Survival outcomes, including local control (LC), progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS), were compared between two cohorts with and without a pathological diagnosis.

RESULTS

The median follow-up for the whole group was 69 months. Patients with a clinical diagnosis were significantly older (p = 0.002). No significant differences were observed between the clinical and pathological diagnosis cohorts in terms of the long-term outcome, with 5-year LC, PFS, CSS, and OS of 87% versus 83% (p = 0.58), 48% versus 45% (p = 0.82), 87% versus 84% (p = 0.65), and 60% versus 63% (p = 0.79), respectively. Recurrence patterns and toxicity were also similar.

CONCLUSIONS

Empiric SBRT appears to be a safe and effective treatment option in a multidisciplinary setting when patients with SPNs highly suggestive of malignancy are unable/refuse to obtain a definitive pathological diagnosis.

Dosimetric comparison of helical tomotherapy and conventional Linac-based X-knife stereotactic body radiation therapy for primary lung cancer or pulmonary metastases

Background

To compare helical tomotherapy (HT) with X-knife stereotactic body radiation therapy (HT-SBRT/X-SBRT) for primary or metastatic lung cancer regarding planning target volume (PTV) coverage, such as homogeneity index (HI), conformity index (CI) and dose-volume histogram (DVH) of organs at risk (OARs).

Methods

We retrospectively analyzed 21 patients receiving definitive radiation treatment for non-small cell lung cancer (NSCLC) or pulmonary metastases at our institution between March 2015 and October 2016. Tumors were irradiated with 4-10 Gy per fraction in 5-15 fractions. Plans were compared according to PTV coverage and OARs sparing.

Results

Significant differences between HT and X-knife were observed for both HI (P=0.003) and CI (P<0.001). The V5 (P=0.001), V10 (P=0.009), V20 (P=0.001), the mean lung dose (P=0.005) of total lung and maximum dose of the spinal cord (P=0.010) were significantly lower in the X-SBRT group than the HT-SBRT group. There were no significant differences for the V30 (P=0.075) and the mean heart dose (P=0.584) between the two groups.

Conclusions

X-SBRT was dosimetrically superior to HT-SBRT, when applied in these tumors' maximum diameters <5 cm. As HT resulted in increased low-dose volume, it is essential to optimize the patient selection in order to avoid severe radiation pneumonitis in HT-SBRT.

Hypo-fractionated stereotactic radiation therapy for lung malignancies by means of helical tomotherapy: report of feasibility by a single-center experience

BACKGROUND

Several experiences in the literature report SBRT as an effective treatment option for medically inoperable early stage non-small cell lung cancer (NSCLC) and oligometastatic disease. The optimal fractionation schedules and total dose remain controversial. In this study, we evaluated the safety in terms of toxicity and efficacy of using of 8-10 fractions schedules with Helical Tomotherapy (HT) for primary and metastatic lung lesions.

METHODS

Between March 2014 and May 2016, a total of 39 patients (median age 72 years, range 26-91) were treated with HT-SBRT for malignant lung lesions: 22 patients with early stage NSCLC, 17 with oligometastases. Patients received 8-10 fractions with lower daily dose for central and ultracentral lesions. Treatment-related toxicity was evaluated using CTCAE v 4.0 scale. Local control (LC), overall survival (OS) and toxicity rates were prospectively collected.

RESULTS

Median duration of RT was 15 days (range 10-26 days) and no interruption occurred. With a median follow-up of 13 months (range 3-29), we reported one G2 pneumonitis (2.6%) and one G2 chest pain (2.6%); no ≥ G2 esophagitis was registered. Actuarial local control rate was 95.5% both at 12 and 24 months for early stage NSCLC and 92.9% both at 12 and 24 months for metastatic patients. OS rate was 94.4 and 92.3% at 1 year, and 94.4 and 83.9% at 2 years in primary and metastatic group, respectively.

CONCLUSIONS

The use of 8-10 fractions schedule HT-SBRT for lung malignancies results in high LC and OS rates with minimal toxicities reported.

Treatment outcomes and patterns of radiologic appearance after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) for lung tumours

OBJECTIVE

To evaluate treatment outcomes and patterns of CT lung injury after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) in a series of inoperable lung lesions.

METHODS

68 patients who were medically inoperable (69 lesions) without evidence of viable extrathoracic disease were included. Dose prescription was driven by tumour location (hilar/pericentral vs peripheral) and/or target volume. 52% of the lesions received a biological equivalent dose (BED10) ≥100 Gy. Assessment of tumour response was based on the Response Evaluation Criteria in Solid Tumours 1.1 criteria coupled with fluorine-18 fludeoxyglucose/positron emission tomography-CT. Toxicity monitoring was focused on treatment-related pulmonary adverse events according to the Common Terminology Criteria for Adverse Events v. 4.0. Acute and late events were classified as radiation pneumonitis (RP) and radiation fibrosis (RF), respectively. Survival curves were calculated using the Kaplan-Meier method. Univariate and multivariate analyses of survival were performed using the Cox proportional hazards model.

RESULTS

After a median follow-up of 12 months (range, 3-31 months), no instances of ≥Grade 4 RP was documented, and clinically severe (Grade 3) RP occurred in 5.8% of the patients. 2 (3%) patients developed a late severe (≥Grade 3) symptomatic RF. No specific pattern of CT lung injury was demonstrated, in both acute and late settings. Median overall survival (OS) and progression-free survival (PFS) for the entire population were 30.8 and 14.1 months, respectively. At multivariate analysis (MVA), BED10 ≥ 100 Gy and KPS ≥ 90 emerged as significant prognostic factors for OS (p = 0.01 and p = 0.001, respectively), and BED10 ≥ 100 Gy for PFS (p = 0.02).

CONCLUSION

Our findings show that HHT adjusted for tumour location and/or target volume is an effective treatment with an acceptable toxicity profile in patients who are medically inoperable with lung tumours and is not associated with a specific pattern of lung injury. Therefore, it can represent a viable option when conventional stereotactic ablative radiotherapy facilities are not available. Advances in knowledge: The present study is among the largest series addressing the role of HHT for inoperable lung tumours. This technique is safe and effective and is not associated with a specific pattern of lung injury, at least at early and average time points.